Squash Blooms but Doesn't Produce

Squash flowers, like the fruits, are edible.

Numerous types of squash (Cucurbita spp.), including zucchini, yellow, acorn and crookneck squashes, are enjoyed as annual garden crops for the edible fruits they produce prolifically. It may cause concern when a prized, healthy squash plant blooms profusely, but the flowers fail to develop into fruit. Understanding the basic anatomy of squash flowers and pollination requirements will generally alleviate a grower's concerns about their squash harvest.

Squash Flowering and Fruiting

Squashes and other cucurbits have separate male and female blossoms. Male blossoms, which are the first to open on the plant, have a thin, straight stem. Female blossoms develop later, are farther out on the vine and have a small, undeveloped fruit at the base of the flower. Only female flowers can yield fruit; and in order for the fruit to develop rather than drop off, the flower must be successfully pollinated. Usually bees transfer squash pollen, but where these insects are lacking it is necessary to transfer pollen by hand to ensure good fruit set. A cotton swab or brush is used to collect pollen from the anthers of the male flowers, and the pollen-covered utensil is brushed against the receptive, shiny stigma in the female flower.